在模块中使用的observeEvent Shiny函数不起作用 [英] observeEvent Shiny function used in a module does not work

问题描述

我正在开发一个应用程序，其中我使用模块来显示不同选项卡的ui内容.但是，似乎该模块无法与主(或父)应用程序通信.它显示正确的ui，但是单击actionButton时不能执行observeEvent功能，它应该更新当前选项卡并显示第二个选项卡.

I'm developing an app in which I use modules to display different tab's ui content. However it seems like the module does not communicate with the main (or parent) app. It displays the proper ui but is not able to execute the observeEvent function when an actionButton is clicked, it should update the current tab and display the second one.

在我的代码中，我创建了一个名称空间函数并将actionButton的ID包裹在ns()中，但是仍然无法正常工作.有人知道怎么了吗?

In my code I have created a namespace function and wrapped the actionButton's id in ns(), however it still does not work. Does anyone knows what's wrong?

library(shiny)

moduleUI <- function(id){

  ns <- NS(id)
      sidebarPanel(

        actionButton(ns("action1"), label = "click")
      )
}

module <- function(input, output, session){


  observeEvent(input$action1, {
    updateTabItems(session, "tabsPanel", "two")
  })
}

ui <- fluidPage(

            navlistPanel(id = "tabsPanel",

                         tabPanel("one",moduleUI("first")),
                         tabPanel("two",moduleUI("second"))
))
server <- function(input, output, session){
  callModule(module,"first")
  callModule(module,"second")

}

shinyApp(ui = ui, server = server)

推荐答案

observeEvent可以工作，但是由于模块只能看到并知道作为输入参数分配给它们的变量，因此它不知道指定的tabsetPanel，因此无法更新它.可以使用无功值解决此问题，该值作为参数传递并在模块内部进行更改.更改后，主应用程序就会知道它并可以更新tabsetPanel:

The observeEvent works, but since modules only see and know the variables given to them as input parameters, it does not know the tabsetPanel specified and thus cannot update it. This problem can be solved using a reactive Value, which is passed as parameter and which is changed inside the module. Once it's changed, it is known to the main app and can update the tabsetPanel:

library(shiny)
library(shinydashboard)

moduleUI <- function(id){

  ns <- NS(id)
  sidebarPanel(
    actionButton(ns("action1"), label = "click")
  )
}

module <- function(input, output, session, tabsPanel, openTab){

  observeEvent(input$action1, {
    if(tabsPanel() == "one"){  # input$tabsPanel == "one"
      openTab("two")
    }else{                     # input$tabsPanel == "two"
      openTab("one")
    }
  })

  return(openTab)
}

ui <- fluidPage(
  h2("Currently open Tab:"),
  verbatimTextOutput("opentab"),
  navlistPanel(id = "tabsPanel",
               tabPanel("one", moduleUI("first")),
               tabPanel("two", moduleUI("second"))
  ))


server <- function(input, output, session){
  openTab <- reactiveVal()
  observe({ openTab(input$tabsPanel) }) # always write the currently open tab into openTab()

  # print the currently open tab
  output$opentab <- renderPrint({
    openTab()
  })

  openTab <- callModule(module,"first", reactive({ input$tabsPanel }), openTab)
  openTab <- callModule(module,"second", reactive({ input$tabsPanel }), openTab)

  observeEvent(openTab(), {
    updateTabItems(session, "tabsPanel", openTab())
  })
}

shinyApp(ui = ui, server = server)

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